Cyclic ketones of the aromatic series and process of making same



Patented .Apr. 8, 1930 UNITED STATES,

PATENT OFFICE rnrrz MAYER, or FBANKFORT-ON-THEMAIN, xoa'r IBILLIG, ornocnsr-on-rnnmm, man noasr, or nornnm-on-rnn-rnnnus, ANDKARL-SCHIRMACHER, or

HOCHST-ON-THE-MAIN, GERMANY, ASSIGNORS TO I.

G. FARBENINDUSTRIE AKTIENGESELLBQHAFT, OF FRANKFORT-ON-THE-MAIN,GERMANY, A CORPORA- T1011 01' GERMANY circnc'xnronns on THE eaomaricsnares AND raocnss or MAKING smn No Drawing. Application filed March f5;1927, Serial No. 175,630, and in Germany March 1'3, 1926.

Our present, invention relates to the preparation of cyclic ketones ofthe aromatic series.

We have found that 'u-B unsaturated fatty acids as well as theiraddition "products'with 5 hydrogen halide and the halides of theseacids, when reacted upon with a hydrocarbon of the aromatic series, ahomologue or substitution product thereof in which at least two adjacentcarbon atoms contain hydrogen asa 1 substituent, in presence of an acidcondensing agent such as aluminium chloride or concentrated sulfuricacid, in absence or presence of asolvent,.at a raised temperature, formaromatic cyclic ketone's. The reaction takes place very readily and theresult obtained thereb is novel and could not be foreseen. Accor 'nglyas the hydrocarbon is substituted there can be obtained by the saidreaction mixtures of isomeric cyclic 'ketones, which can generally beeasily separated. It. is of no consequence whether there are used theolefin'e carboxylic acids or their addition products with h drogenhalide, because the latter are trans ormed during the reaction 2 intothe former. It is also immaterial wheth er the free acids of theirhalides are used'as starting material, in all cases there are obtainedthe same final products.

Our new process permits to arrive in an easy technical way at a catnumber of heretofore unknown or di cultly obtainable cyclic ketones. Anumber of the cyclic ketones in question constitute valuableintermediate products for the manufacture of dyestuflfs andpharmaceutical products. The followin examples serve'to illustrate V ourinvention, ut they are not intended to limit itthereto; theparts arebweightz r 1) Into a suspension of 2 parts of alu- 40 minium chloride in10 parts of benzene is slowly run at ordinary temperaturea solution of11 parts of fi-chlorpropionic acid and 16 parts of benzene, Thetemperature is then raised to boiling and kept so for several hours.

After decomposition with ice and hydrochloric acid the reaction mixturemay be worked up by subjectin it to distillation with steam, duringwhich t ere distils over at fir'fl only; benzene v and afterwards thecyclic iietone W) (u-indanone) which solidifies into crystals,

of the constitution:

maintained for two hours. After the mass has been decomposed with iceand hydrochloric acid, the toluene is blown oif and the remaining massis worked up as indicated in Example 1. Thus there is obtained a liquidmixture which is com osed of two isomeric cyclic ketones of the ollowingformula:

GHa

(3H OH: v a ,3. a co cg 1 (3) A mixture of 11 parts of B-chlorpropionicacid and 22 parts of chlorobenzene is run at ordinarytemperatu're into amixture of 27 parts. of aluminium chloride and 10 parts of chloroberzene, whereupon the temperature is raisedup to 100 G. or above and aftersome hours the resulting mass is further treated as indicated inExample 1. Thus a mixture composed of two isomeric cholrinated cyclic'ketones is obtained/ When this mixture-is recrystallized from alcohol,there separates first almost only the cyclic ketone v m i I H: v I co/ ZThis ketone hasitsmelting point at 91-92 C.

From the mother liquor there may, moreover, be separated the cyclicketone of the formula:

' CH: I x11,

which has its iiielting point at 79 C. g

stance,

-gradually raised until the boiling point of the benzene is reached andis kept so for some hours. After the mass has been worked up in theusual manner, the volatile cyclic ketone of the formula:

' is obtained, which boils at 255 0.

(5) In an analogous manner is obtained by using chlorobenzene a mixtureof the following cyclic ketones:

I-&CO OH' md CIQCO The former ketone'crystallizes and melts at about 470., the latter is liquid and boils at 275 C.

(6) When using m-xylene, the cyclic ke-- tone of the formula:

cm om is formed which boils at about 250 C.

(7) To 27 parts vof aluminium chloride suspended in 22 parts ofchlorobenzene are 7 added in small portions at ordinary temperature 9parts of crotonic acid, whereupon the temperature is raised to theboiling point and the mass is stirred at this temperature for some time.*After cooling, the mass is worked up in the usual manner. Thus amixture of the two isomeric cyclic ketones is obtained which isidentical with the mixture produced according to Example 5.

(8) To 50 parts of m-dichlorobenzene and 27 parts of aluminium chlorideare added at ordinary temperature 9 parts of solid crotonic acid and themass is heated for some time to 100 C. After the mass has been worked upin the usual manner, the cyclic ketone of the following formula:

A 01 in. n

c1 00 is obtained, which melts at 67-70 C.

Analogous products are obtained by the action of crotonic acid upono-dichlorobenzene (the product bein an oil boiling at about 200 0.),upon Twomobenzene the product being a mixture of a solid pro uct meltingat 83 C. and a liquid product boiling at about 260 C. upon m-xylene (theon ice and then rendered slightly alkaline by adding sodium carbonate.The nitrobenzene is separated from the aqueous alkaline solution. Afterhaving added to the latter hydrochloric acid, an oily acid precipitateswhich, after drying, solidifies into a light, brittle resin.

In order to transform this product into the cyclic ketone, 100 parts ofit are heated at about 50 C. for one'hour with 500 parts of nitrobenzeneand 85 parts of phosphorous pentachloride and there are then added at 10C. 70 parts of aluminium chloride. The whole is then stirred for about24 hours at 30 C. whereupon the mass is poured on ice and thenitrobenzene removed by distillation with steam. The cyclic ketone thusformed may be further purified by boiling it with a solution of sodiumcarbonate. In order to obtain it in a perfectly pure state, it isadvisable to distill the crude product in the vacuum and torecrystallize the distillate from alcohol. The resulting product formsbrilliant yellow needles melting at PLO-142 C. which dissolve insulfuric acid to a yellow solution with a yellowish-green fluorescence.

(10) A solution of 14,2 parts of a-methylnaphthalene and 12,7 partsB-chlorpropionic acid chloride is gra duallyintroduce'd into asuspension of 30 parts of aluminium chloride in 120 parts of carbondisulfide. After the mass has been worked up in the usual manne'r, thereaction product first formed is introduced into concentrated sulfuricacid' and heated to 90-100 C. during half anhour. On pouring it in waterthe cyclic ketone of the formula:

CHI

separates which melts at 133 C.

(11) If the ,B-chlorpropionic acid chloride as used in Example 10 isreplaced by 14,1 parts of ,B-chlorbutyric acid chloride and the otheroperations are carried out according to the said example the cyclicketone of the foris obtained which melts at 67-68 C.

In the following claims the term (z-B4111- saturated fatty acid compoundis intended to include a-B-unsaturated fatty acids and t-heirhydrogenhalide addition products as 7 well as'their halides; and the terma'romatic compound isintended to comprise aromatic hydrocarbons andtheir homologues and sub stitution products. I

We claim:- 1. The process for preparing cyclic keJtones of the aromaticseries, which consists in subjecting an unsaturated fatty acid compound.

to reaction with an aromatic compound in which at least two'adjacentcarbon atoms contain hydrogen as a substituent in presence of aluminiumchloride at a temperature'of about 40 C. to 140 .C.

2. As new products cyclic ketones of the general formula:

wherein R represents a substituted aromatic radical of the groupincluding the benzene. and naphthalene series.

3. As new products cyclic'ketones of; the general formula:

(/ m il wherein X may stand for hydrogen, halogen or one of the groupshydroxyl, oxyalkyl or alkyl or two adjacent Xs may be 'a ring linked tothe benzene nucleus, in which formula however at least one X signifies asubstituent other than hydrogen.

4. As newproducts cyclic ketones of the general formula:

wherein Hlg stands for a halogen atom and" X stands for hydrogen or ahalogen atom.

. 5. As new products halogen-containing cyclic keto nes of the followingformula:

In testimony whereof, we aflix our signa- 'tures.-

PROFESSOR-DR. FRITZ MAYER. KURT BILLIG. KARLHORST. KARL SCHIRMACHER.

